The present invention relates generally to photographic diffuser lightbanks or soft boxes and more specifically to releasable rod or pole anchors for rods or poles that support lightbanks in extended, outstretched configuration.
Photographic diffuser lightbanks, also sometimes known as light boxes or soft boxes, are commonly used by photographers and film makers to control the distribution of light on subjects. Devices of these types are disclosed, for example, in the following U.S. patents:
Lightbank assemblies typically include a diffuser panel for scattering light rays emanating from a bright light source, which may include a light bulb or filament, a hood or body formed from fabric or other soft material with a reflective interior surface for confining and directing the light rays from the light source to the diffuser panel, and a support structure for supporting the reflective hood and diffuser panel over the light source. The mounting structure typically comprises a ring-shaped frame or other mounting component for attachment of the light bank assembly to the light source, and a plurality of support rods or poles that extend forwardly and outwardly from the ring-shaped frame to support the reflective hood and diffuser panel. The support rods or poles are usually formed from resilient metal, graphite, plastic, or other materials that can be bowed against an inherent bias or resistance by application of external forces, but which spring back to their original shapes upon removal of such forces. One common approach for mounting the support rods or poles to the ring-shaped frame includes cylindrical holes in the ring-shaped frame. In lightbank assemblies of these types, the proximal ends of the respective support rods are inserted into the holes in the ring-shaped frame so that they extend forwardly and outwardly from the ring-shaped frame at an angle that will cause them to be resiliently strained or deformed into a bowed or arced state when the reflective hood is mounted on the rods, while the fabric of the reflective hood body is stretched in tension. This combination of bowing and tensile forces or stresses enables the rods to support and hold the reflector hood and diffuser panel of the lightbank in their operative position extending forward and outward from the ring-shaped frame.
Before, after, and even during photography and video sessions, it is often necessary to move the lightbanks. Since many lightbanks are relatively large and bulky, it is often desirable that they be collapsed, folded, or otherwise broken down or disassembled before they can be transported efficiently. Unfortunately, it can be difficult to collapse lightbanks of the type described above. The tension in the reflective hood body mounted on the strained and deformed support rods or poles generates considerable compressive forces between the proximal ends of the rods and the surfaces of the holes in the ring-shaped frame in which they are anchored as well as between the distal ends of the rods and the outer edges of the reflective hood that are mounted on the distal ends of the rods, thereby making it difficult to remove the ends of the rods from the holes in the frame. In order to remove the support rods from the holes in the frame and collapse these lightbanks it is necessary to force the rods into even more compression and further deform them enough to pull either the proximal end out of the hole in the ring-shaped frame or to disconnect the distal end of the rod from the reflective hood body. A relatively high degree of physical strength can be required to undertake this action, especially in large light bank assemblies.
There remains, therefore, a continuing need for lightbank assemblies that can be conveniently extended and collapsed. An example of an attempt to alleviate this problem is illustrated in U.S. Pat. No. 6,076,935, issued to Kester, in which Velcro(trademark) end flaps and pockets have some benefits, but they still require much physical strength and manipulation, especially in mounting. Therefore, they work best for smaller lightbank structures.
Another approach is used in the Lowel Rifa-lite(trademark), manufactured by Lowel Light Manufacturing, Inc., in Brooklyn, N.Y., wherein the reflective hood and support rods are shaped and assembled in a manner that has some similarities to an umbrella for extending and collapsing the reflective hood. It has the attractive feature of the rods being permanently attached to the ring-shaped fame, which slides longitudinally on a central pole or base. However, that assembly is better suited to small lightbank structures.
Consequently, in spite of those prior art lightbank structures, there remains a need for a better rod mounting or anchoring device that works well and is convenient for large, as well as small, lightbank assemblies. To be commercially viable, any such assemblies must be capable of being efficiently manufactured.
The present invention is an improved lightbank assembly that can be conveniently set up and collapsed. One embodiment of the invention includes a plurality of pivotal and latchable anchor blocks pivotally mounted on a ring-shaped fame for mounting the support rods or poles of a light bank assembly to a base of light source. The latchable anchor blocks or mounts are movable between an operative or latched position at which the support rods are anchored in the blocks and extended forwardly and outwardly to extend and support the lightbank reflective hood and diffuser panel in an outstretched configuration, and a released position at which the support rods and reflective hood can be collapsed. Other embodiments of the invention include clamps for releasably clamping the mounts in the operative position.